WDPN31 PGTW 212100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 22W (TWENTYTWO) 
WARNING NR 006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 13.1N 128.2E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 429 NM EAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: WESTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 18 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS AN
ELONGATED AND BROAD CIRCULATION WITH ASSOCIATED DEEP CONVECTION TO
THE WEST AND SOUTHWEST OF THE ASSESSED LOW-LEVEL CIRCULATION CENTER
(LLCC). SPIRAL BANDS OF DEEP CONVECTION ARE BEGINNING TO WRAP INTO
THE LLCC WHILE TD 22W CONTINUES TRACKING WESTWARD. THE INITIAL
POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON ANIMATED EIR AND
THE INITIAL INTENSITY OF 30 KTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED ON PERSISTENCE AND THE AGENCY AND AUTOMATED FIXES LISTED
BELOW.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: SOUTHWEST EXTENSION OF THE SUBTROPICAL 
RIDGE (STR) TO THE NORTHEAST 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T2.0 - 30 KTS
   KNES: T2.0 - 30 KTS
   CIMSS SATCON: 40 KTS AT 211800Z
   CIMSS ADT: 39 KTS AT 211800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TD 22W IS FORECAST TO TRACK NORTHWESTWARD OVER
THE NEXT 36 HOURS UNDER THE STR EXTENSION TO THE NORTHEAST. AS IT 
APPROACHES THE SUBTROPICAL RIDGE CENTERED OVER SOUTHEAST CHINA AND AS 
THE SYSTEM APPROACHES LUZON, THE STR WILL ELONGATE AND SPLIT INTO A 
SOUTHWESTERN AND NORTHEASTERN PORTIONS. THE PEAK INTENSITY PRIOR TO 
LANDFALL IS ASSESSED AT 50-55 KTS, DETERMINED BY MARGINALLY FAVORABLE 
CONDITIONS, INCLUDING HIGH SEA SURFACE TEMPERATURES, HIGH OCEAN HEAT 
CONTENT, STRONG OUTFLOW, OFFSET BY 15-20 KTS VERTICAL WIND SHEAR. TD 
22W WILL START TRACKING WESTWARD, BEING STEERED BY THE NEWLY SPLIT 
STR 
COMPONENT CENTERED NORTH OF HAINAN ISLAND. THE SYSTEM IS FORECAST TO 
MAKE LANDFALL IN THE PHILIPPINES BETWEEN TAUS 36 AND 48. 22W IS THEN
FORECAST TO WEAKEN AS IT TRANSITS OVER THE MOUNTAIN RANGES OF
NORTHERN LUZON. SYSTEM IS EXPECTED TO REEMERGE OVER SOUTH CHINA SEA
BETWEEN TAUS 48 AND 72 AND DRIVEN BY SIMILARLY FAVORABLE CONDITIONS
IS FORECAST TO START RE-INTENSIFYING, REACHING PEAK INTENSITY OF 55
KTS BY TAU 96. PAST TAU 96, TD 22W IS FORECAST TO WEAKEN, AS IT
BEGINS INTERACTING WITH THE TERRAIN AND APPROACHES SLIGHTLY COOLER
WATERS.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN GOOD
AGREEMENT, PARTICULARLY UNTIL LANDFALL IN THE NORTHERN
PHILIPPINES, WITH A CROSS-TRACK SPREAD OF 45 NM JUST PRIOR TO
LANDFALL. TRACK GUIDANCE FOR RE-EMERGING OVER SOUTH CHINA SEA IS
FAIR, WITH A LARGER ALONG-TRACK SPREAD AND A COUPLE OUTLIERS
(NAVGEM, JGSM) TAKING THE SYSTEM ON A MORE NORTHWESTWARD TRACK THAN
THE REMAINDER OF THE AIDS. JTWC TRACK FORECAST IS LAID CLOSE TO
MULTI-MODEL CONSENSUS, HEDGED TOWARDS THE GFS SOLUTION AND AWAY
FROM THE TWO OUTLYING MODELS. IN TERMS OF INTENSITY, THE JTWC
FORECAST IS ON THE HIGHER SIDE OF THE CONSENSUS, KEEPING IT CLOSER
TO GFS. MODEL GUIDANCE IS IN FAIR AGREEMENT THROUGHOUT THE FORECAST
PERIOD, WITH HAFS BEING THE ONLY OUTLIER, ESTIMATING THE
INTENSIFICATION OF THE SYSTEM OUT TO NEARLY 70 KTS PRIOR TO
LANDFALL OVER LUZON, AS WELL AS 65 KTS PEAK INTENSITY BY TAU 96.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: MEDIUM
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: MEDIUM//
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